Abstract��
With piezoelectric actuators as control elements, the basic equations of shape control for adaptive truss was formulated. A mathematical model of optimal actuator placements was presented, in which the actuator locations and the control voltages were taken as design variables, and the weighted presentation of the shape precision, control energy and number of actuators was taken as the objective function. This model subjected to the strength of the structure, the limit of nodal displacement and the maximum control voltage of actuators. Because the actuators and the ordinary bars have different element stiffness, every reasonable allocation of actuators could result in the change of whole stiffness matrix. If genetic algorithm was directly applied, an extremely large number of structural analysis would be needed. In order to decrease the number of structural analysis, a new method was proposed, in which the multi-point approximation, genetic algorithm and quadratic programming were combined. The results of examples show that the proposed method has high efficiency.